1# SPDX-License-Identifier: GPL-2.0
2#
3# Building vDSO images for x86.
4#
5
6# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
7# the inclusion of generic Makefile.
8ARCH_REL_TYPE_ABS := R_X86_64_JUMP_SLOT|R_X86_64_GLOB_DAT|R_X86_64_RELATIVE|
9ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE
10include $(srctree)/lib/vdso/Makefile
11
12# Sanitizer runtimes are unavailable and cannot be linked here.
13KASAN_SANITIZE			:= n
14KMSAN_SANITIZE_vclock_gettime.o := n
15KMSAN_SANITIZE_vgetcpu.o	:= n
16
17UBSAN_SANITIZE			:= n
18KCSAN_SANITIZE			:= n
19OBJECT_FILES_NON_STANDARD	:= y
20
21# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
22KCOV_INSTRUMENT		:= n
23
24VDSO64-$(CONFIG_X86_64)		:= y
25VDSOX32-$(CONFIG_X86_X32_ABI)	:= y
26VDSO32-$(CONFIG_X86_32)		:= y
27VDSO32-$(CONFIG_IA32_EMULATION)	:= y
28
29# files to link into the vdso
30vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o
31vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
32vobjs32-y += vdso32/vclock_gettime.o
33vobjs-$(CONFIG_X86_SGX)	+= vsgx.o
34
35# files to link into kernel
36obj-y				+= vma.o extable.o
37KASAN_SANITIZE_vma.o		:= y
38UBSAN_SANITIZE_vma.o		:= y
39KCSAN_SANITIZE_vma.o		:= y
40OBJECT_FILES_NON_STANDARD_vma.o	:= n
41
42# vDSO images to build
43vdso_img-$(VDSO64-y)		+= 64
44vdso_img-$(VDSOX32-y)		+= x32
45vdso_img-$(VDSO32-y)		+= 32
46
47obj-$(VDSO32-y)			+= vdso32-setup.o
48
49vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
50vobjs32 := $(foreach F,$(vobjs32-y),$(obj)/$F)
51
52$(obj)/vdso.o: $(obj)/vdso.so
53
54targets += vdso.lds $(vobjs-y)
55targets += vdso32/vdso32.lds $(vobjs32-y)
56
57# Build the vDSO image C files and link them in.
58vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
59vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
60vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
61obj-y += $(vdso_img_objs)
62targets += $(vdso_img_cfiles)
63targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
64
65CPPFLAGS_vdso.lds += -P -C
66
67VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
68			-z max-page-size=4096
69
70$(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
71	$(call if_changed,vdso_and_check)
72
73HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
74hostprogs += vdso2c
75
76quiet_cmd_vdso2c = VDSO2C  $@
77      cmd_vdso2c = $(obj)/vdso2c $< $(<:%.dbg=%) $@
78
79$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
80	$(call if_changed,vdso2c)
81
82#
83# Don't omit frame pointers for ease of userspace debugging, but do
84# optimize sibling calls.
85#
86CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
87       $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \
88       -fno-omit-frame-pointer -foptimize-sibling-calls \
89       -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
90
91ifdef CONFIG_RETPOLINE
92ifneq ($(RETPOLINE_VDSO_CFLAGS),)
93  CFL += $(RETPOLINE_VDSO_CFLAGS)
94endif
95endif
96
97$(vobjs): KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
98$(vobjs): KBUILD_AFLAGS += -DBUILD_VDSO
99
100#
101# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
102#
103CFLAGS_REMOVE_vclock_gettime.o = -pg
104CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg
105CFLAGS_REMOVE_vgetcpu.o = -pg
106CFLAGS_REMOVE_vsgx.o = -pg
107
108#
109# X32 processes use x32 vDSO to access 64bit kernel data.
110#
111# Build x32 vDSO image:
112# 1. Compile x32 vDSO as 64bit.
113# 2. Convert object files to x32.
114# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
115# so that it can reach 64bit address space with 64bit pointers.
116#
117
118CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
119VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
120			   -z max-page-size=4096
121
122# x32-rebranded versions
123vobjx32s-y := $(vobjs-y:.o=-x32.o)
124
125# same thing, but in the output directory
126vobjx32s := $(foreach F,$(vobjx32s-y),$(obj)/$F)
127
128# Convert 64bit object file to x32 for x32 vDSO.
129quiet_cmd_x32 = X32     $@
130      cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
131
132$(obj)/%-x32.o: $(obj)/%.o FORCE
133	$(call if_changed,x32)
134
135targets += vdsox32.lds $(vobjx32s-y)
136
137$(obj)/%.so: OBJCOPYFLAGS := -S --remove-section __ex_table
138$(obj)/%.so: $(obj)/%.so.dbg FORCE
139	$(call if_changed,objcopy)
140
141$(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE
142	$(call if_changed,vdso_and_check)
143
144CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds)
145VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
146
147KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO
148$(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
149$(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32
150
151KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
152KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
153KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
154KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
155KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32))
156KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
157KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32))
158KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32))
159KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_CFI),$(KBUILD_CFLAGS_32))
160KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
161KBUILD_CFLAGS_32 += -fno-stack-protector
162KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
163KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
164KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
165
166ifdef CONFIG_RETPOLINE
167ifneq ($(RETPOLINE_VDSO_CFLAGS),)
168  KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS)
169endif
170endif
171
172$(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
173
174$(obj)/vdso32.so.dbg: $(obj)/vdso32/vdso32.lds $(vobjs32) FORCE
175	$(call if_changed,vdso_and_check)
176
177#
178# The DSO images are built using a special linker script.
179#
180quiet_cmd_vdso = VDSO    $@
181      cmd_vdso = $(LD) -o $@ \
182		       $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
183		       -T $(filter %.lds,$^) $(filter %.o,$^) && \
184		 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
185
186VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 \
187	$(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack
188GCOV_PROFILE := n
189
190quiet_cmd_vdso_and_check = VDSO    $@
191      cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
192
193#
194# Install the unstripped copies of vdso*.so.  If our toolchain supports
195# build-id, install .build-id links as well.
196#
197quiet_cmd_vdso_install = INSTALL $(@:install_%=%)
198define cmd_vdso_install
199	cp $< "$(MODLIB)/vdso/$(@:install_%=%)"; \
200	if readelf -n $< |grep -q 'Build ID'; then \
201	  buildid=`readelf -n $< |grep 'Build ID' |sed -e 's/^.*Build ID: \(.*\)$$/\1/'`; \
202	  first=`echo $$buildid | cut -b-2`; \
203	  last=`echo $$buildid | cut -b3-`; \
204	  mkdir -p "$(MODLIB)/vdso/.build-id/$$first"; \
205	  ln -sf "../../$(@:install_%=%)" "$(MODLIB)/vdso/.build-id/$$first/$$last.debug"; \
206	fi
207endef
208
209vdso_img_insttargets := $(vdso_img_sodbg:%.dbg=install_%)
210
211$(MODLIB)/vdso: FORCE
212	@mkdir -p $(MODLIB)/vdso
213
214$(vdso_img_insttargets): install_%: $(obj)/%.dbg $(MODLIB)/vdso
215	$(call cmd,vdso_install)
216
217PHONY += vdso_install $(vdso_img_insttargets)
218vdso_install: $(vdso_img_insttargets)
219
220clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so*
221